Inclusion Criteria:

• Postmenopausal woman OR a man at least 30 years of age (who no longer have bone growth)

• In the opinion of the investigator:

  • The patient must have severe osteoporosis (defined as a low bone mass AND a fracture related to osteoporosis), and be at high risk for fracture despite currently available therapies
  • Patients should have failed or been shown to be intolerant to currently commercially available osteoporosis therapies. (Failure of therapy: fracture, or significant loss of bone mass)
  • There should be no other medical causes of the osteoporosis (called idiopathic osteoporosis) except for low estrogen (in women) or low testosterone (in men)
• In the opinion of the investigator, the patient can learn to use the pen type injection delivery system and will be able to use it either alone or with appropriate assistance
• Must be able to understand and sign an approved informed consent document
• Must be able to come in for follow-up visits for the duration of the study.

Exclusion Criteria:

• High blood calcium levels, high parathyroid hormone levels in the blood, high levels of a blood test called alkaline phosphatase that haven't been explained yet.
• Known or suspected bone diseases other than osteoporosis
• Any medical condition that might increase a patient's baseline risk for bone tumors (including prior radiation to the skeleton, Paget's disease, previous bone tumors).
• Recent or currently active kidney stone, OR major problems with kidney function
• Serious ongoing medical problems incompatible with the study (as assessed by the investigator)